NEW YORK (TheStreet) -- Emirates Airline finalized an order for 150 Boeing 777X planes, worth $56 billion at list prices, after its surprise cancellation of a $16 billion order for 70 Airbus A350 planes in June.

Boeing said in a statement that the deal also includes purchase rights for another 50 planes that could boost the value to about $75 billion at list prices. The deal follows Emirates' cancellation in June of a $16 billion order to buy 70 A350 planes from Airbus.

Emirates President Tim Clark said the 777X is due for delivery in 2020 and will provide the airline operational flexibility, more passenger capacity and fuel efficiency.

Boeing has said the 777X, a larger model of its 777 wide-body, would be about 12% more fuel-efficient than competing jets and have 10% lower operation cost. It's already partnered with General Electric (GE) Aviation in making fuel-efficient engines for the plane.